Computers generally utilize disk drives for data storage and retrieval, such as magnetic recording hard disk drives that include a head assembly for reading and/or writing data on a rotatable magnetic disk. In such systems, the head assembly is typically attached to an actuator arm by a head suspension assembly (HSA) comprising a head suspension and an aerodynamically designed slider onto which a read/write head is provided. When the head is positioned over a spinning disk during usage, the head configuration is at least partially controlled by balancing a lift force that is caused by an air bearing generated by the spinning disk and acting upon the slider, and an opposite bias force of the head suspension. In operation, the slider and head are designed to “fly” over the spinning disk at high speeds and at precisely determined distances from the disk surface. The slider can be considered to be spaced from the disk by a gas lubrication film that can be referred to as an “air bearing,” as the lubricant gas is typically air.
Recently, some disk drive enclosures are being designed for use with helium rather than air, which provides a number of advantages. For one advantage, drives filled with helium experience less friction than those filled with air, such that the disks and the arms to which the sliders are attached suffer less turbulence. With the decreased turbulence, thinner disks can be spaced closer to each other in a disk drive stack, thereby increasing the storage capacity of the disk drive. In addition, the lower levels of friction in helium drives can result in decreased power consumption and lower operating temperatures. In some cases, the lower turbulence can also reduce the amount of noise produced by the drive.
In order to maintain a volume of helium in a sealed disk drive enclosure, the enclosure will generally be hermetically sealed. Such a sealing of the enclosure is important to maintain the thickness of the helium acting as a gas lubrication film between the head and the disk, which impacts the overall performance of the head. However, such sealing can be difficult to accomplish since any port or opening in the enclosure that provides communication with the inner area of the enclosure provides a potential leak point through which helium can escape. One such opening and potential leakage point is a port in the cover through which air is evacuated from the enclosure and helium is introduced to the enclosure. There is therefore a need for a disk drive enclosure having a reliable configuration for the introduction of helium into its internal area and for minimizing or eliminating helium leakage.